Make domain configurable via env #3
Description
As of now the domain for Netcup is provided through an URL parameter, which makes not a lot of sense.
The initial idea was that Fritz!Box would pass the domain. For a multi domain scenario that clearly makes no
sense and should be removed.
Instead the domain should be converted to a local configuration like any other parameter for the updaters.
Only the IPs need to be passed from Fritz!Box.